Dean Donaldson

Napa County UCCE has been busy with a small start-up grant to teach composting. I believe six counties had similar grants from CAWMCB. We are in the middle of it all as we speak. Grant calls for training of Master Composters and their teaching of local residents. We patterned it after Placer/Nevada and Sonoma programs. Local grower group organizing into a 'Sustainable Growing Group' has some major corporate players. They ask provocative questions for which research does not yet exist. Terms are tossed around that need definition:


These are used in advertisements and by in-speak agency folks. Local grower approach is not to use compost unless they get a benefit from it.

  1. It costs too much to purchase for nutrient value.
  2. Physical mass difficult to haul, store and distribute within commercial grape vine trellis systems.
  3. Unknown amounts needed to control weeds.

Unknown repeat application timing. Compost sources see it as disposal problem, but growers see it as a cash flow issue. With our wet winters and clay loam soils we have access with heavy equipment for only a short time after harvest. Research needs to be done about surface soil benefits over time. Clyde Elmore and I have talked about this with Pritchard, et al and may submit a DANR grant to explore this. I note Oregon St Univ seems to be studying impacts of weed management practices on surface biomass and microbe populations. Big grower fear up here is not heavy metals, but is soil active root pathogens such as Oak Root Fungus. Does it survive composting? Dr Raabe says nothing in literature about it,( but suspects it may be possible) this could be an excellent research project. Is green wast ebetter than compost? or vice-versa?